Camera distance measuring apparatus

Abstract

This distance measuring apparatus comprises a first light projecting device for projecting a distance measuring light to an object to be photographed in the central part of a picture; second and third light projecting devices for projecting distance measuring light to objects in the peripheral parts of the picture; a first distance measuring operating device for receiving the reflected light from the object in the central part of the picture and outputting the first distance information in response to the object distance; second and third distance measuring operating devices for receiving reflected light from objects in the peripheral parts of the picture and outputting second and third distance informations in response to the object distances; and a photographing distance determining device for determining a photographing distance based on the above mentioned distance information. The photographing distance determining device has a first judging part for judging the first distance information to be a photographing distance in case the first distance information is within a predetermined distance range; a second judging part for judging either of the first and second distance informations to be a photographing distance in case the first distance information is a distance nearer than the predetermined distance range and the second distance information is also a distance nearer than the predetermined distance; and a third judging part for judging the first distance information to be a photographing distance in case the first distance information is in a distance farther than the predetermined distance.

What is claimed is: 
     
       1. A camera distance measuring apparatus wherein a light projecting means and a light receiving means are arranged in the lengthwise direction of a camera to detect the position of the reflected light from an object to be photographed of a light projected by the light projecting means, comprising: a light projecting means provided with:   a first light projecting means for projecting a light toward the vicinity of the center of a picture to be photographed,   a second light projecting means for projecting a light toward the light projecting means side from said vicinity of the center of the picture to be photographed and   a third light projecting means for projecting a light toward the light receiving means side from said vicinity of the center of the picture to be photographed;   a first distance detecting means for detecting by said light receiving means the light receiving position of the reflected light from the object of a beam projected by said first light projecting means and detecting a first distance from this light receiving position to the object;   a second distance detecting means for detecting by said light receiving means the light receiving position of the reflected light from the object of a beam projected by said second light projecting means and detecting a second distance from this light receiving position to the object;   a third distance detecting means for detecting by said light receiving means the light receiving position of the reflected light from the object of a beam projected by said third light projecting means and detecting a third distance from this light receiving position to the object; and   a distance determining means for determining photographing distance by using said first, second and third distances; said distance determining means having the following judging means:   a first judging means whereby it is judged whether said first distance is within a predetermined range or not and, in case it is within this predetermined range, said first distance will be determined to be a photographing distance,   a second judging means whereby, in case said first distance is in a distance nearer than the predetermined range, unless said second distance is a distance nearer than said predetermined range, said second distance will be determined to be a photographing distance and, in case said second distance is a distance nearer than the predetermined range, the first distance will be determined to be a photographing distance and   a third judging means whereby, in case said first distance is in a distance farther than said predetermined range, said second distance or said third distance will be determined to be a photographing distance.   
     
     
       2. A camera distance measuring apparatus according to claim 1 characterized in that said second judging means will determine said second distance to be a photographing distance only in case said second distance is not a distance nearer than said predetermined range and in case said third distance is not also a distance nearer than said predetermined range. 
     
     
       3. A camera distance measuring apparatus according to claim 1 characterized in that said third judging means selects the nearest distance of said second distance and third distance and determines it as a photographing distance. 
     
     
       4. A camera distance measuring apparatus according to claim 1 characterized by comprising fourth and fifth light projecting means for projecting lights further outside the distance measuring optical axes of said second and third light projecting means and fourth and fifth distance detecting means for detecting the light receiving positions of the reflected lights from the object of beams projected by the fourth and fifth light projecting means and detecting the fourth and fifth distances from the light receiving positions to the object to be photographed so that, in case it is judged by said third judging means that said first distance is farther than said predetermined range, said second distance will be replaced with the first distance, said fourth or fifth distance will be replaced with the second distance and a judgment will be made by said first judging means and second judging means. 
     
     
       5. A camera distance measuring apparatus comprising: a first light projecting means for projecting a light toward the vicinity of the center of a picture to be photographed;   a first distance detecting means for detecting by said light receiving means the light receiving position of the reflected light from the object of a beam projected by said first light projecting means and detecting the first distance from said light receiving position to the object.   a first comparing means for comparing whether said first distance is in a predetermined distance range;   a first photographing distance determining means for determining said first distance to be a photographing distance in case said first distance is in the predetermined distance range as a result of the comparison of said first comparing means;   a second light projecting means for projecting a light at least toward the direction on said first light projecting means side from the center of said picture to be photographed in case said first distance is in a distance nearer than said predetermined distance range as a result of the comparison of said first comparing means;   a second distance detecting means for detecting by said light receiving means the light receiving position of the reflected light from the object of a beam projected by said second light projecting means and detecting the second distance from said light receiving position to the object;   a second comparing means for comparing said second distance and a first predetermined distance on the near distance side of said predetermined distance range with each other; and   a second photographing distance determining means for determining said first distance to be a photographing distance in case said second distance is nearer than said first predetermined distance as a result of the comparison of said second comparing means and determining said second distance to be a photographing distance in case said second distance is farther than said first predetermined distance.   
     
     
       6. A camera distance measuring apparatus according to claim 5 wherein said first photographing distance determining means is further provided with a third comparing means for comparing said first distance and the second predetermined distance on said predetermined distance range side with each other so that, as a result of the comparison of said third comparing means, in case said first distance is farther than said second predetermined distance, a photographing distance may be determined by using said second distance. 
     
     
       7. A camera distance measuring apparatus according to claim 6 further comprising: a third light projecting means for projecting a light toward the direction reverse to said first light projecting means side from the center of said picture to be photographed in case said first distance is in a distance nearer than said predetermined distance range as a result of the comparison of said first comparing means; and   a third distance detecting means for detecting the light receiving position of the reflected light from the object of a beam projected by said third light projecting means and detecting the third distance from said light receiving position to the object;   so that, as a result of the comparison of said third comparing means, in case said first distance is farther than said second predetermined distance, the nearer side of said second distance and third distance will be determined to be a photographing distance.   
     
     
       8. A camera distance measuring apparatus comprising: a first light projecting means for projecting a distance measuring light to an object in the central part of a picture;   a second light projecting means for projecting a distance measuring light to an object in a peripheral part adjacent in the horizontal direction on the picture to said central part;   a distance measuring operating means for receiving the reflected lights from the objects of said first light projecting means and second light projecting means and outputting respectively the first and second distance informations in response to the object distances; and   a photographing distance determining means for determining the photographing distance on the basis of said first and second distance informations wherein:   in case said first distance information is of a value corresponding to a predetermined distance range or in case both of said first distance information and second distance information are of a value corresponding to a distance nearer than said predetermined distance range, the photographing distance will be determined on the basis of said first distance information, and   in case said first distance information is of a value corresponding to a distance farther than said predetermined distance range or in case said first distance information is of a value corresponding to a distance nearer than said predetermined distance range and said second distance information is not of a value correspoding to a distance nearer than said predetermined distance range, the photographing distance will be determined on the basis of said second distance information.   
     
     
       9. A camera distance measuring apparatus according to claim 8 wherein said second light projecting means will project said distance measuring light in case it is judged by said photographing distance determining means that said first distance information is not of a value corresponding to said predetermined distance range. 
     
     
       10. A camera distance measuring apparatus for measuring the distances of a plurality of objects to be photographed within a picture, comprising; a light projecting means for projecting distance measuring light to a first point within the picture and an object to be photographed in a peripheral part adjacent in the horizontal direction on the picture to said first point;   a distance operating means for receiving the reflected light from said plurality of objects and outputting distance informations in response to the object distances; and   a photographing distance determining means for determining the photograhing distance on the basis of the distance information of said first point in case it is judged from the output of said distance operating means that the object of said first point is in the predetermined distance range or that both of the first point and the object the peripheral part are in a distance nearer than said distance range and determining the photographing distance on the basis of the distance information of said peripheral part in case it is judged that the object of said first point is a distance farther than said predetermined distance range or that the object of the first point is a distance nearer than said distance range but the object of the peripheral part is not a distance nearer than said distance range.   
     
     
       11. A camera distance measuring apparatus according to claim 10 wherein said first point is substantially in the central part of the picture to be photographed. 
     
     
       12. A camera distance measuring apparatus according to claim 10 wherein said first point is a center point of at least three distance measuring points arranged adjacently in the horizontal direction of the picture. 
     
     
       13. A distance measuring apparatus in a camera having a light projecting means and a light receiving means, said light projecting means and said light receiving means being arranged in a predetermined direction of the camera to detect a position of an object by light reflected from the object to be photographed due to a light projected by said light projecting means, comprising: a distance detecting means for detecting object distances from respective light receiving positions of the reflected light from objects to be photographed of respective lights projected by said light projecting means in a plurality of directions including the vicinity of a center of a scene to be photographed; and   a photographing distance determining means for determining a second distance to be a photographing distance when a first distance near the center of said scene to be photographed is nearer than a predetermined distance and the second distance detected by the reflected light of the light projected toward a side of the scene is farther than said predetermined distance.   
     
     
       14. A camera distance measuring apparatus comprising: a first light projecting means for projecting a distance measuring light to a central part of a scene to be photographed;   a first distance measuring operating means outputting a first distance information in response to a light receiving state of a light reflected from said central part of the scene;   a judging means for comparing said first distance information with at least one predetermined value for judging from said first distance information whether the distance measuring light of said first light projecting means is being normally projected or not;   a second light projecting means for projecting a distance measuring light to a peripheral part of the scene responsive to a judging means result that a distance measuring light of said first light projecting means is not normally projected;   second distance measuring operating means outputting a second distance information in response to a light receiving state of a light reflected from said peripheral part of the scene;   a photographing distance determining means for determining a photographing distance from said first distance information when it is judged by said judging means that the distance measuring light of said first light projecting means is being normally projected to the main object and for determining a photographing distance from said second distance information when it is judged that the distance measuring light of said first light projecting means is not being normally projected.   
     
     
       15. A camera distance measuring apparatus according to claim 14 wherein: said judging means includes means for judging that said distance measuring light is being normally projected to the main object when said first distance measuring information is of a value corresponding to a predetermined distance range or when both said first distance information and said second distance information are of a value corresponding to a distance nearer than said predetermined distance range and means for judging that said distance measuring light is not being normally projected to the main object when said first distance information is of a value corresponding to a distance farther than said predetermined distance range or when said first distance information is nearer than said distance range and said second distance information is not nearer than said distance range.   
     
     
       16. A camera distance measuring apparatus according to claim 14 wherein said judging means further comprises means for comparing said second distance information with at least one predetermined value. 
     
     
       17. A camera distance measuring apparatus according to claim 14 wherein said first light projecting means includes means to generate a spot-like beam and said distance detecting means comprises means for determining when said beam only partially impinges upon a center object to indicate that light is not being normally projected. 
     
     
       18. A photographing distance determining method of projecting distance measuring light to a plurality of objects to be photographed including at least a central part of a scene, receiving the reflected light from said plurality of objects and determining a photographing distance on the basis of distance informations corresponding to the object distances, comprising the steps of: (a) projecting a distance measuring light to an object in the central part of the scene and receiving a reflected light to determine a distance information;   (b) judging whether the distance information of said central part object is in a predetermined photographing distance range or not;   (c) determining a photographing distance from the distance information of said central part object when it is judged by step (b) that the central part object is in the predetermined photographing distance range;   (d) projecting a distance measuring light to an object of a part adjacent to the central part and receiving a reflected light to determine a distance information when it is judged by step (b) that the distance information of the central part object is out of the photographing distance range;   (e) judging from the respective distance information of the adjacent part and said central part whether said central part object is in an extremely near photographing range or not;   (f) determining a photographing distance from the distance information of said central part object in when it is judged by step (e) that the central part object is in the extremely near photographing range; and   (g) determining a photographing distance from the distance information of said adjacent part when it is judged by step (e) that the central part object is not in the extremely near photographing range.   
     
     
       19. A photographing distance determining method in a camera distance measuring apparatus comprising the steps of: providing a first light projecting means and projecting a light therefrom toward the vicinity of the center of a scene to be photographed; providing a second light projecting means and projecting a light therefrom toward the direction on a side of the scene to be photographed; providing a first distance detecting means for detecting a light receiving position of a light reflected by an object due to a beam projected by said first light projecting means and detecting a first distance from this light receiving position to the object; providing a second distance detecting means for detecting a light receiving position of a light reflected by an object due to a beam projected by said second light projecting means and detecting a second distance from this light receiving position to the object:   comparing said first distance with a predetermined distance, comparing said second distance with said predetermined distance and determining the second distance to be the photographing distance when said first distance is nearer than said predetermined distance and said second distance is farther than said predetermined distance.